断层切割围岩的巷道稳定性数值分析

Numerical Analysis on Roadway Stability by Fault Cutting Surrounding Rock

为了分析断层切割围岩巷道的采动地压,应用FLAC^(3D)建立基于参数弱化法和接触面法的不同断层数值计算模型,模拟巷道开挖及附近矿体开采过程,对比分析两种方法的巷道围岩应力变化。分析表明:因这两种方法处理断层的方式不同,使得断层与围岩的连续性变化不一致,因而导致巷道开挖的初始地压显现差异较大;模拟断层切割巷道围岩选用何种方法应依据现场断层的工程地质分析;这两种方法计算的矿体采动对巷道稳定性的影响规律趋于一致,北侧矿体采空是引起1 330 m中段巷道围岩的拉应力值增加的主要原因,断层是引起1 330 m中段巷道围岩的拉应力值增加的次要原因,这与铅硐山铅锌矿地压显现的实际相吻合。

The intention of this paper is to analyze the pressure of the roadway in the fault cutting surrounding rock.The FLAC3D was used to establish two kinds of different numerical models with faults,one is the parameter weakening method,one is the contact surface method.Through the simulation of roadway excavation and the mining process of nearby the ore body,the stress changes of roadway surrounding rock between the above two methods were compared and analyzed.The results of the study indicate that,these two methods deal faults with different ways,which causes the continuity of the faults and the surrounding rock is inconsistent,thus resulting in a huge difference between the two initial ground pressures.As far as practical application is concerned,the method of simulating the surrounding rock of roadway by fault cutting should be based on the engineering geological analysis of the actual fault.The influence of ore body mining on the stability of roadway tends to be consistent according to the calculation results.The main reason for the increase of tensile stress of the surrounding rock of roadway in middle of 1330 m is the north ore body mining,and the secondary cause is the faults.The results are consistent with the actual situation of the ground pressure appearance in Qiandongshan lead-zinc mine.